U.S. officials stressed that they consider the crisis humanitarian, citing the danger for children of traveling thousands of miles in the hands of smugglers

(Updates with comments from Honduran government, paragraphs 8-10)

By Patricia Zengerle

PANAMA CITY, July 1 (Reuters) - U.S. Secretary of State John Kerry said on Tuesday Washington would work with Central America to address the root causes of an immigration crisis, but kept up the Obama administration's tough message that undocumented children would be deported.

"We obviously understand people who want to do better, and who look for a better life," Kerry said as he met leaders from Honduras, El Salvador and Guatemala, countries from which tens of thousands of children have fled to the United States in recent months.

"But at the same time, there are rules of law, and there is a process and there is false information that is being spread about benefits that might be available to these young people who are looking for that better life," he added.

Kerry was in Panama for the inauguration of the country's new president, Juan Carlos Varela, and he combined the trip with meetings to address a crisis that is straining U.S. resources and roiling partisan tensions in Washington over immigration.

President Barack Obama said on Monday he was sending Kerry to Central America to address the problem, in a speech pledging to act alone to revamp the U.S. immigration system and protect the border after hopes of persuading congressional Republicans to pass broad reform legislation officially died.

Kerry's visit followed one by Vice President Joe Biden to Guatemala on June 20 to discuss the exodus of children that is also threatening to complicate Washington's ties with its allies in Mexico and Central America.

The absence of Hernandez raised some eyebrows after the new Honduran president also skipped the meeting with Biden while on a trip to the World Cup in Brazil. That followed criticism of the United States in his inaugural address in January, when he said Central America was suffering from U.S. drug consumption.

Asked about the Panama talks, Honduran deputy foreign minister Roberto Ochoa told Reuters that protocol dictated that Aguero meet Kerry and that Hernandez wanted an "informal private meeting" with the U.S. secretary of state to discuss migration.

"There's a way of communicating among equals, and this is an old practice in relations between countries," Ochoa said.

Tens of thousands of children from Guatemala, El Salvador and Honduras are showing up illegally, often without parents, at the Texas border. Their numbers could reach 90,000 this year and 150,000 next - up from only about 6,000 in 2011.

U.S. officials stressed that they consider the crisis humanitarian, citing the danger facing children traveling thousands of miles in the hands of smugglers. "The lives of children cannot be put at risk this way," Kerry said.

However, Washington also wants Central American countries to do more to fix their economies, for example by integrating their trade, State Department officials said.

"Until the Central Americans really get past some of the arguing among themselves and focusing on going it alone ... they're not going to overcome these problems," one said.

U.S. Republicans blame lax border security and Obama's moves toward easing immigration rules for encouraging Central Americans to risk the long journey north to escape poverty, crime and violence at home.

Obama blames Republicans for refusing to pass legislation that would address broader immigration issues, such as whether to provide a path to citizenship for millions of undocumented immigrants in the United States.

Activists and some of Obama's fellow Democrats in Congress say many of the children would be eligible for asylum. (Additional reporting by Gustavo Palencia in Tegucigalpa; Reporting by Patricia Zengerle; Editing by Cynthia Osterman and Mohammad Zargham)